Cooling Maintenance Evidence Report
Cooling Resilience Assessment, one cooling system and one maintenance question.
Sample document. Example facility and simulated observations.
The question
Can pump P-01 be isolated for a bearing inspection while P-02 carries the cooling load under today's operating conditions?
Observed evidence
P-01 drive-end vibration rose from 2.1 to 3.4 mm/s RMS over nine days. Bearing housing temperature was 4 C above its own baseline. No BMS alarm was reached. P-02 passed a start/stop test; full-load performance was not verified.
Shared dependencies
P-01 and P-02 share a suction header, a discharge path and a differential-pressure control. Lead/lag sequencing is held in the BMS. The electrical path was not assessed.
Decision status
Review required
Not authorised for isolation. The pack supports a next-check plan, not the work itself.
1. Scope and question
SystemPrimary chilled-water pump set P-01 and P-02, serving the secondary loop and the CRAH units on halls A and B.
QuestionIsolation of P-01 for a bearing inspection, with P-02 in duty, at today's operating load.
PeriodNine days of assessment observation, plus review of 12 months of BMS trends and maintenance records.
Evidence sourcesBMS trends, maintenance history, temporary vibration and temperature points on P-01 and P-02, site walk and control narrative.
2. Observed evidence
- P-01 drive-end vibration rose over nine days while flow and differential pressure stayed within the usual operating range.
- P-01 bearing housing temperature was above its own baseline on the last four days. No BMS alarm was reached.
- P-02 started and ran without a reported fault during a short start/stop test. Its full-load flow and head were not verified in this period.
- The site's last full-load performance record for P-02 is older than the current operating condition and could not be used as a current capacity statement.
3. Dependencies
HydraulicCommon suction header, common discharge path and a shared differential-pressure control. The pumps are not independent cooling paths.
ControlLead/lag sequence, differential-pressure set point and valve positions are held in the BMS. A changeover depends on the sequence behaving as designed.
LoadThe pumps support the CRAH units serving halls A and B. The distribution of IT load across those halls was not verified in this assessment.
Out of scopeElectrical resilience, chiller capability, control-system changes and full-facility modelling were not assessed.
4. Limits and unknowns
- The remaining cooling capacity of the P-02 path at current load has not been established.
- Valve positions, authority and the actual changeover sequence have not been tested under live load.
- P-02 full-load performance and its maintenance history need review before it is treated as the remaining duty pump.
- No hydraulic model or validated scenario model was used. This report does not provide a capacity rating, a failure probability or a redundancy classification.
5. Next checks before a decision
- Measure P-02 flow and head at current load with a temporary point, using the same basis as the P-01 observations.
- Confirm the lead/lag sequence, differential-pressure control and valve positions with the BMS engineer.
- Review P-02 maintenance history, last performance test and any known restrictions.
- Confirm the IT load distribution across the CRAH units and the operating conditions the site will use for the decision.
- Walk the isolation, abort and restoration procedure with the authorised person and agree the checks that stop the work.
6. Approval and verification
Site approvalIsolation, changeover and any test require the authorised site person under the permit-to-work and change-control procedures.
ProtectionThis report does not replace BMS alarms, equipment protection or site procedures.
Post-maintenanceAfter the bearing work, repeat the P-01 observations under comparable load, verify P-02 performance after its run and compare with this pack.
ClosureRecord whether the condition changed, close or reopen the question, and update the evidence pack for the next maintenance decision.
Sample document with an example facility and simulated observations. It does not authorise isolation, does not replace BMS alarms, protection or site procedures, and does not provide a capacity rating, a failure probability or a redundancy classification.